Platen for printing machines



1919 2 Sheets-Sheet 1 ll lt M w m W H a C. A. KELLOGG PLATEN FOR PRINTING MACHINES Original Filed Dec. 15

QM .H

6M H i Dec. 11, 1923.

Dec. 11 1923.

c. A. KELLOGG PLATEN FOR PRINTING MACHINES Original Filed De c. 15.

2 Sheets-Sheet 2 TTORN Y Patented Dec. 11, 1923.

CARL A. KELLOGG, OF BROOKLYN, NEW YORK.

rLA'rEn roe PRINTING MAoHInEs Application filed December 15, 1919, Serial No. 344,956. Renewed Noyemberzfl, 19,2 1 Serial To 5 20/ 107)? it may concern:

Be it known that I, CARL A. KnLLoGG, a citizen of the United States, residing in the city of New York, borough of Brooklyn,

county of Kings, and State of New York,- have' invented a certain new and useful Platen for Printing Machines, of whichthe following is a specification.

This invention is a platen for printing machines and is adapted to form one member of the printing couple adapted for rolling co-action duringthe periods of impression.

While numerous forms of platen, adapted to constitute one member of a printing couple, have been suggested, the curved face, with which most of said platens are provided, and which serves as the impression surface thereof, is formed on a true are of a circle, developed from a common center through. a given radius. Platens so constructed are found, in practice, to produce inferior results since, when subjected to rolling co-action with a form, the pressure of the platen on the form is not uniform regardless of the material from which the platen is constructed, and to so position and operate the platen that the direction of pressure along the entire surface of the platen is in a straight line between the point of contact of the platen with the form bed and the support of the platen.

Another object of the invention is to provide a platen which will be stiff and rigid and capable of operating on one or more forms whether positionedend to end, or side by slde.

Features of the invention, other than those specified, will be apparent from the hereinafter detailed description taken in conjunction with the accompanying draw ngs.

. I the." c m a yingd aw n s I have Figure'l i at .1). plan" View of t e. Plats-F embodying the present manag Figure 2 is a ensue-vanes o-f'the ee f showing the manne r of mounting it in" a printing machine.

Figure 3 is an end elevation of the structure as shownin Figure 2,"the supporting shaft of 'the' platen being s own mesa t ema d i i Figure 4 is a diagrammatic view illustrating the operation of the platen] In constructingthe light, strong'and rigid platen of this invention, it is preferal ili formed asshown in the drawings by a curved plate l substantially rectangular'in plan and provided at its opposite ends with upstanding brackets 2, the upper portions of which are formed into bearings, 31 The curved plate 1 is preferably stiffened longitudinally. and transversely by means of ribs h i are t erewith Whi t b acket 2 are stiffened by COIItiIllliIlgtllG center tud n lr that .a we 1. iii W dly the 'insid of-ea h b rdie 2., t e ear n y' hie bhsir e qn'every t ong a see peers pa ed an one egrtremely lightweight, whereby the l' i Q ti P ate-i d l i g Ql i Ql i m h z d nd teamed amiaew gh 1 speeds withou re u in shocks, "vibrat on-f or in? "an w theil springing during impression.

Associated witheach lateral edge of the platen is a bearerfi which isf set into a recess 7 extending along the lower edge of the platen. Each bearer 6' is secured to one end of the plate ,1 by machine screws" or bolts 8 which pass through slots 9 in the bearers and thread into the "plate This bolt and slot connection is provided .toallow of a djustmentfof the bearings, to-regulate the pressure of the platen "while on -iI np on an pr t ee; s hfadius ment is obtained by means of adjusting nuts 10, h. ork 1 m thheede 5 129% 11- o g the manipu ate or these hu he desired elevation and consequent pressure, maybe readily had; 'f y The pla en is, p rted a eases-tread by a shaft 16 which is provided with off set or crank portions 17, so that, as the crank shaft 16 revolves in fixed bearings 18, which are adjustable toward and away from the platen, the platen will be raised and lowered in accordance with the positions of the cranks 17 of said shaft.

In the preferred manner of employing the platen of this invention, the bottom curved surface of the plate 1, constitutes the impression surface of the platen and positioned at either'end of said platen and in a longitudinal medial line of the impression surface is a trunnion 19, adapted to cooperate with a fixed vertical guide in the Y complementary member of the printing couple between impressions. hen the crank shaft 16 rotates, the cranks 17 will travel through a circular path, the path of the axis of'each crank 17 being shown in the dot and double dash line 20 in Figure 4:. The axis of thiscircular path is the axis of rotation ofthe crank shaft 16 whichis designated in Figure 4; by121. In Figure 4c, the center of the trunnion 19is designated by 22, and the '3 position of theplaten, when the crank is on bottom dead center with the members of the printing couple onthe center of impression, is shown in full lines 23. The dash line position 24 shows the platenat the instant it commences the impression and the dot and dash line 25 shows the platen at the instant it completes and leaves impression.

The object of i this invention, as heretofore stated, is to so shape the curved impression surface ofthe platen, that from the time it partakes of the position shown at 24 and.

commences rolling. co-action with the form, untiljthe time when it leaves the position 25, it will have a line contact with the flat form with which it co-operates and will force the paper to be printedaipon, against the form at a constant pressure throughout theentire impression period.

essary that the curve of the impression surface be formed along accurately defined lines. I have found that the curve of the impression surface is dependent upon several factors among which may be mentioned the width of the platen;'the 'radiusofthe throw of the ln orller toaccomplish this purpose it is neccrank shaft, and the distance from the axis of the crank of said shaft to the face of the form. If any of these factors are chan ed, the curve will correspondingly changefbut the method of determining this curve will now be fully explained so that the invention may be adapted to various conditions.

in order that the method of laying out the curve of the impression surface may be understood and practised l have, for the purpose of illustration taken seven arbitrary points on the impression surface which successively come into engagement with the surface of the form. Any number of points might be taken for exan'iple but the number chosen will sulliee for explanation. These seven points I have identified with. thereference numerals 37 to 43 inclusive, 37 being the point of the beginning of impressionand 4C3 a point midway of impression. On the line X, which represents the height of the form, I have designated points 27 to 32 inclusive and 22 which are the points 'on the surface of the formwith which the points 37 to 43, respectively, will successively contact during the first half of an impression. Lines A, B, C, D, E, F and G are drawn from the points 27 to 32 inclusive, to the center 21 of the throw of the crank 17, and lines a, b, c, d, e, f and g are drawn from the points 87 to 43 inclusive, to the center 26 of the crank 17. The correct shaping of the impression surface of the platen may be computed by reference to these lines and points.

lnlaying out the section of the platen, as shown in Fig. 4:, the distances which the spaced seven points along its impression surface are from thecenter 26 may be stated as a formula, to wit 7 Distance a distance -27 to 21distance 21 to 26,

or v 7 Distance 3'? to 26:27 to 21-21to 26 w or to place the formula in words :The distance from any point on the impression surface to the center of the crank is equal to the distance from the axis of the crank throw to. the corresponding point of the plane of the form surface with taken point ofthe impression surface will engage during impressiomaninus the ra-.

dius of throw of the crank, or, in other words, line A distance 21 to 27) minus the radius of the crank throw (distance 21-to 26) equals. line (1 (distance?!- to 26). Similarly lines A, B, C, D, E, F and G minus the radius of the crank throw give lines a, 1). 0,11. 6, .f and g, respectively. 1 The shape ofcorrect contour for the impression surfaoemay thus be obtained. I Y is v e in other words, the distance between any particular po nt onthe i-mpression surface ofthe platen and the center ofthe crank 17, when added tothe radius of the throw of the crank shaft 16 must be equal to the distance which the '26 of the crank is oscillated into a position wherein a line drawn from the axis 21 of the shaft 16 to the said point on the surface of the form will pass through the cen ter 26 of the crank.

In the manner described any and all points on the surface of the platen may be accurately and mathematically determined so that the resulting platen will be capable of true and proper rolling co-action on a flat form during impression.

In accordance with the present invention, the curved face of the platen is thus shaped, so that when positively driven by the crank shaft 6 and guided by the trunnions 9 all points of the impression surface will successively engage with the form and with the same pressure, so that uniform impressions result. A marked advantage of this construction in combination with the crank peration of the platen is that when any point of the platen is in engagement with the form, this point is in alinement with the direct thrust of the crank on the platen.

To illustrate, it will be noted, that when the impression is being made, at the point 27 in the form, the crank 17 will be on dead and the direct application of power to the impression surface allows the machine to be made light and consume less power than when operated through indirect connections.

Through the proportioning and operation of the parts as shown and described relative to Figure tic. the period of impression of the platen constitutes a relatively small proportion of the double operation thereof. As

shown in this figure. the impression oe-- cupies but 60 of the rotation of the crank shaft 16 leaving 300 when the platen is off impression. This enables a printing ma chine embodying the present invention to be run at much higher speeds than has heretofore been possible due to the fact that a maximum time is allowed for the shifting of a web between impressions, when the. form is stationary.

The ma chine will runsmoothly, without vibratlon,

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

i. In a printing machine, a printing couple embodying a flat form and a platen having a curved in'ipression surface, and a crank for operating the platen to move IlfOlI and off impression, said platen being adapted for substantially line contact with the form. during impression and the curved impression surface of theplaten beii'ig of such conformation that the crankwill, atall times. be on dead center with the line contact be tween the platen and form during impression. p

2. In a printing machine, a printing couple embodying a fiat form and a platen haying a curved impression surface, and a crank shaft for operating the platen to more it on and off impression, said curved'impression surface of the platen being of such conformation that the distance from any point on i the impression surface to the center of the crank is equal to the distance from the axis of the crank shaft to the corresponding point in the plane of the printing surface of the form with which the said point-onthe impression surface will engage during in,-

pression, minus the radius of the throw of the crank.

3. In a printing machine, a printing couple embodying a flat form and a platen having a curved impression surface, a crank shaft for operatingthe platen'to move it on and off impression, and means for guiding said movements of the platen, said curved impression surface of the platen being of such conformation that the distance from any point on the impression surface to the center of the crank is equal to the distance from the axis of the crank shaft to the corresponding point in the plane of the printing surface of the form with which the saidforms the impression surface of the platen,

brackets projecting from the opposite face of said plate and atthe opposite ends thereof to provide an operating support for the platen, and ribs or webs formed on said plate for imparting rigidity thereto.

6. Ina printing machine, a platen provided with a curved impression-surface, means for actuating the platen, and trunnions for guiding the platen during its operations, said trunnions being positioned at either 'side of the platen with their axes in alincinent with one another and projecting from the plane of the curved impression surface.

7. in a printing machine, a platen provided with a curved impression surface, means for operating the platen, and means for guiding the platen during operation, said guiding means serving to allow of oscillation of the platen on an axis passing through the plane of the curved impression surface.

8. A printing press platen provided with means for mounting it for rocking move ment on an axis passing through its impression surface which is of irregular curvature in the direction of movement of the platen.

9. A printing press platen having a curved impression surface of irregular curvature and provided with trunnions at its impression surface for mounting the platen for rocking movement.

10. A printing press platen provided with a longitudinally curved impression surface embodying a succession of curves of different radii, and means for mounting the platen for rocking movement on a trans verse axis substantially at its impression surface.

11. A printing press platen having an impression surface which is transversely straight and longitudinally curved on a curve struck from a moving center which most closely approaches the impression surface at a point midway of the length of said surface, and means for mounting said platen to rock back and forth longitudinally of the platen.

12. A rocking impression platen for printing presses provided with a curved impres sion surface extending longitudinally of the.

direction of rocking movement of the platen and different portions of which surface are formed on arcs of different radii, and means for mounting the platen for rocking movement on an axis passing through its curved impression surface.

13. A printing machine embodying a flat form, a platen provided with a longitudinally curved impression surface embodying a succession of arcs struck from different centers, and means for mounting the platen for rocking movement in line contact with the form on an axis substantially at its curved impression surface.

14. A printing machine embodying a platen provided with. a curved impression surface struck from the plurality of centers, and adjustable bearers associated with the opposite sides of the platen and extending substantially the full length thereof and curved to correspond with the curvature of the impression surface.

15. A printing press platen having a 1ongitudinally curved impression surface struck from a ,moving center and provided at its lateral sides with alined trunnions positioned substantially at the impression surface of the platen.

In testimony whereof, I have signed my name to this specification.

CARL A. KELLOGG. 

